
*{
  margin: 0;
  padding: 0 ;
}
.function1{
    width: 100%;
    height: 40px;
}
.function1 button{
    float: right;
    margin: 0 5px;
}
.function2{
    padding: 10px 50px;
}
.function2 ul{
    list-style: none;
}
.function2 ul li{
    float: left;
    padding: 20px;
}
.header{
    height: 50px;
    width: 100%;
}
.myul li{
    margin: 0 15px;
}
.header_span{
    /*vertical-align: center;*/
    line-height: 50px;
    font-family: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Heiti SC", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
    font-size: 18px;
}
.contain{
    width: 100%;
}
.contain_head{
    display: flex;
    flex-direction: row-reverse;
    margin: 10px
}
.contain_body{
    width: 90%;
    padding-left: 100px;
    margin: 0 auto;
    padding-bottom: 50px;
}
.contain_body  ul{
    list-style-type: none;
    overflow: auto;
//消除浮动
}
.contain_body  ul li{
    float: left;
    width: 33.3%
}
#all_course  li{
        border: 2px solid black;
        height: 180px;
        width: 250px;
        margin:20px;
        background: yellow;
      }
      h2{
        margin:0;
      }
      .siglebutton{
        margin:10px 3px 10px 3px; 
      }
      .sigleCourse{
        width: 100%;
        background: white;
        height: 70%;
      }
      .singleCourseBottom{
        display: flex;
        flex-direction: row;
        margin: 0 auto;height:30%;
      }